| Abstract [eng] |
In this study the influence of additives on the properties of thermoplastic cellulose diacetate was investigated. The plasticisers used to plasticise cellulose diacetate were as follows: polyethylene glycol, triacetin and triethyl citrate. The plasticisers made up 15 %, 25 % and 35 % of the compound. In order to improve the insertion of the plasticisers into the compound, ultrasound was applied on the samples for the duration of 1 hour, 2 hours and 4 hours. Cellulose diacetate which was plasticised using polyethylene glycol was mixed with citric acid in order to impede the migration of the plasticiser from the composition. The melt flow index results showed positive influence of the ultrasound on the insertion of the plasticiser between the polymer’s macromolecules. The samples on which the ultrasound was applied for 2 hours had the highest plasticity. When the amount of plasticiser was increased the melt flow index and relative elongation also increased, however tensile strength and modulus of elasticity decreased. Compounds with the highest elasticity were achieved using triacetin additive. Based on the results of infrared spectroscopy, compositions in which citric acid was used, formed chemical bonds between citric acid, polyethylene glycol and cellulose diacetate when high temperature was applied. The results of the measurements of the wetting angle showed that the films which were plasticised using triacetin or triethyl citrate were more hydrophobic than additive-free cellulose diacetate film, however films which were plasticised using polyethylene glycol were more hydrophilic. Thermogravimetric analysis revealed that the migration of the plasticiser from the compound was slower in the samples which ultrasound was applied on compared to the samples ultrasound was not applied on. |
